Fever in chicken pox - how long does it last?

DS has gone down with chicken pox. First spots started to appear on Thursday evening so we're 3 full days in. He hasn't had a bad fever since Thursday but tonight was red and hot and it was 39C. I've given him his full dose of calpol and he's asleep now.

He had a fever the day before the spots came out but nothing since until now. Is this normal for chicken pox or should I be considering taking him to the doctor tomorrow if he's stil feverish? Most of the stuff I can find on google says the fever precedes the spots, but is quiet on whether the fever then lasts through the course of pox or whether it should have gone away once the spots arrive.

Do the spots look red and sore? They can get infected so if any doubt then call the GP surgery and explain. They may prefer he attends when the surgery is otherwise empty? How is he in himself. If he is very lethargic, esp if vomiting or other symptoms then call out of hours doctor for more advice rather than waiting.

Thanks - he had a much better night than Saturday and lots have crusted over. Still a bit of a temp but not as bad. Keeping an eye on one or two and will give dr a call as think some are looking infected. I guess that could be causing the temp

DS2 had a fever in and off for the first 3 days of spots. Every time a crop of spots erupted he seemed to spike a temp and was very lethargic with no appetite. Once all the spots were out he seemed to pick up and was well in himself. I gave regular paracetamol and ibuprofen for those days with Piriton for the itch